内臓感覚 Viscerosensory System

P3-1-149 ラット腰仙部脊髄副交感神経核ニューロンにおけるin vivoパッチクランプ法を用いたシナプス応答の解析 In vivo analysis of synaptic responses evoked in parasympathetic preganglionic neurons in the rat spinal cord ○箱崎敦志1,2,3, 井本敬二1,2, 林勧生3, 佐々木英治3, 河谷正仁4, 古江秀昌1,2 ○Atsushi Hakozaki1,2,3, Keiji Imoto1,2, Yukio Hayashi3, Eiji Sasaki3, Masahito Kawatani4, Hidemasa Furue1,2 生理研・神経シグナル1, 総研大・生理2, 大鵬薬品工業（株）3, 秋田大院・医・機能展開4 Dept Information Physiol, NIPS, Aichi, Japan1, Sch Life Sci, SOKENDAI, Aichi, Japan2, TAIHO pharm. Co., LTD, Ibaraki, Japan3, Dept Neurophysiol, Akita Univ Grad Sch Med, Akita, Japan4 Coordinated movement of the bladder, urethra and external urethral sphincter in the lower urinary tract (LUT) is essential for the bladder filling and voiding. The activations of these organs are precisely controlled by the central nervous system including the spinal cord. Parasympathetic preganglionic nucleus (PGN) in the lumbosacral spinal cord plays an important role of in regulating different pelvic organ function including micturition and defecation. Although pharmacological and behavioral approaches have been well utilized to study the spinal control of LUT functions, the cellular mechanism, however, is still unclear. In this study, we developed an in vivo extracellular recording and whole-cell patch-clamp recording techniques to investigate how the spinal cord controls the LUT function at the synaptic level. The firing frequency of spinal dorsal horn neurons in the PGN was synchronously changed with the intravesical pressure. The electrophysiological properties of PGN in L6 spinal cord slices with an attached dorsal root were also studied. Monosynaptic excitatory postsynaptic currents mediated through Aδ and C fiber were elicited in PGN neurons. The newly developed in vivo recording techniques in addition to the lumbosacral slice-patch recording are useful for elucidating the detailed mechanism for spinal control of LUT function.

P3-1-150 延髄孤束核におけるシナプス入力様式の形態的違い―末梢由来（下神経節）vs局所由来（孤束核） Morphological differences of synaptic inputs from axonal boutons of peripheral (the nodose ganglion) and local (the nucleus of tractus solitarious) origin ○根岸義勝1, 河合良訓1 ○Yoshikatsu Negishi1, Yoshinori Kawai1 慈恵医大・医・解剖1 Dept Aanat, Jikei Univ Sch Med, Tokyo1 A large amount of the information processing that happens in the brain occurs in the microcircuitry, which receives various inputs including peripheral and local ones. For comprehensive understanding of the mechanisms by which the microcircuitry processes these various inputs, it is essential to elucidate the weight of them. In this study, to estimate the relative anatomical weight of the inputs from peripheral and local sources, we analyzed distribution patterns of synaptic boutons formed on axons of the nodose ganglion (NG) and the nucleus of tractus solitarious (NTS) neurons, respectively. When biotinylated dextran amine (BDA) was injected into the NG and NTS, axonal boutons arising from the NG and NTS neurons were found in the NTS, respectively. Synaptic boutons were identified by immunostaining with the presynaptic markers synaptophysin, vesicular glutamate transporter (VGLUT) 1, and VGLUT2 antibodies. Fluorescent microscopic dual labeling showed colocalization of immunoreactivity for synaptophysin, VGLUT1, or VGLUT2 with BDA in boutons in the NTS, suggesting that boutons on both axons of the NG and NTS neurons are synapses. BDA labeled axons of the NTS neurons colocalized VGLUT2 while those of the NG neurons colocaized not only VGLUT2 but also VGLUT1. Almost BDA labeled axons from the NG neurons were thicker than those from the NTS neurons. Relatively large boutons formed on axons arising from the NG neurons were found to be colocalized with a large VGLUT1-positive structure or few synaptophysin- or VGLUT2-positive ones. The average length of inerbouton intervals was larger in the NG neuron axons than in the NTS ones. This study suggests that peripheral inputs are few strong while local inputs are many weak.

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